The present application relates to an information processing apparatus, an information recording medium, an information processing method, and a computer program. more particularly, the present application relates to an information processing apparatus for storing various kinds of content for which content use management is required and for realizing use management of each of subdivided data units, to an information recording medium for use therewith, to an information processing method for use therewith, and to a computer program for use therewith.
Various software data, such as audio data such as music, image data such as movies, game programs, and various kinds of application programs (hereinafter, these will be referred to as “content”), can be stored as digital data on a recording medium, for example, a Blu-ray disc in which a blue laser is used, a DVD (Digital Versatile Disc), an MD (Mini Disc), and a CD (Compact Disc). in particular, a Blu-ray disc using a blue laser is a disc capable of high-density recording and is capable of recording a large amount of video content or the like as high-quality data.
Digital content is stored in these various information recording media and is provided to a user. The user reproduces and uses content in an owned reproduction device, such as a PC (Personal Computer) or a disk player.
In general, sales rights or the like of most content, such as music data and image data, are held by the creator thereof or the seller thereof. Therefore, when distributing these pieces of content, it is common practice that a fixed use limitation is imposed, that is, use of content is permitted for an authorized user so that copying without permission or the like will not be performed.
According to a digital recording apparatus and a recording medium, images and audio can be repeatedly recorded and reproduced without degrading them. Therefore, problems such as those described below have occurred: the distribution of illegally copied content via the Internet, the distribution of so-called pirated discs produced using a CD-R and the like, onto which content has been recorded, and wide use of copied content stored in a hard disk of a PC or the like.
It is possible for a DVD or a large-capacity recording medium, such as a recording medium using a blue laser whose development has progressed in recent years, to record a large amount of data for one to several movies as digital information on one medium. When it has become able to record video information and the like as digital information in the manner described above, it has become increasingly important to prevent illegal copying and protect a copyright owner. In recent years, in order to prevent such illegal copying of digital data, various technologies for preventing illegal copying to digital recording apparatuses and recording media have been implemented.
For example, in a DVD player, a content scramble system is adopted. in the content scramble system, video data, audio data, and the like are encrypted and recorded on a DVD-ROM (Read Only Memory). a key used to decrypt encrypted data is given to a licensed DVD player. The license is given to a DVD player that is designed to comply with predetermined operation definitions such that illegal copying is not performed. Therefore, in the licensed DVD player, by decrypting the encrypted data recorded on a DVD-ROM by using a given key, images and audio can be reproduced from the DVD-ROM.
On the other hand, since a non-licensed DVD player does not have a key for decrypting encrypted data, it is not possible to decrypt encrypted data recorded on a DVD-ROM. as described above, in the content scramble system, a DVD player that does not satisfy conditions required at license time cannot play a DVD-ROM having digital data recorded thereon, so that illegal copying is prevented.
On the other hand, as a data communication network has become popular in recent years, a so-called home network has penetrated, in which household electrical appliances, a computer, and other peripheral devices are network-connected, so that communication among the devices is made possible. The home network provides convenience and comfortability to a user in such a way that data processing functions of the devices are shared and content is transmitted and received among the devices by performing communication among the network-connected devices. it is expected that the home network will become more popular in the future.
With the progress of such networking, it becomes more often that content stored on an information recording medium is used by accessing it from a device that is connected to a home network. The above-described illegal copying prevention system of the related art is based on the concept that, for example, content reproduction is permitted in only one licensed reproduction apparatus. Therefore, in a network-connected device, sufficient consideration has not been given to deal with processing in which a device into which a recording medium is loaded, for example, a home server or a player is accessed from another network-connected device, for example, a PC or a TV, and the content is reproduced via a network.
In the related art, usage such that one piece of content stored on a recording medium is used by one reproduction apparatus is predominant. Therefore, it is suffice to perform use management of content by setting a content using right, such as a license, to the content or the reproduction apparatus. However, at the present time in which an information recording medium has a larger capacity and devices in a home have become increasingly digitized and networked, content use management structure differing from the past structure has become necessary. Specifically, demands described below have occurred.
(1) Realization of the configuration in which a plurality of pieces of content are recorded on a recording medium, and use management is made possible for each piece of content.
(2) Realization of use of content in a specific network such as a network in a home, that is, content use management structure for permitting content reproduction by a network-connected device or content copying from a home server.
(3) Realization of the configuration in which information necessary for content reproduction, for example, a key used for decrypting content, is securely distributed to a specific user via a network.
There has been a demand for realizing the configuration of (1) to (3) described above.